Process of making lake colors.



UNITED. STATES PATENT OFFICE.

FRIEDRICH Max WINTER, or EKIIRBRI'ICK GERMAN-Y.

To all whom it may concern:

. Be it known that I, FRIEDRICH MAX WIN- IT ER, a subject of-the German Emperor, residing at Fahrbriicke, in, Saxony, in Ger many, have invented certain new and useful Methods of Manufacturing Lake Colors, of

. and silica present during the reaction being difficult or expensive treatment involving the p so proportioned relatively. to the quantity of alumina in each articular case, that the aluminum silicate ormed has a molecular constitution suitable for the particular coloring matter to be used. For use with the azo dyes, for example the neutral silicate Al. ,(),.3SiO is particularly suitable. For use with basic coloring matter an acid silicate havlng, approximately, the composition to be preferred, since most basic dyesilcan be very easily fixed on this silicate, without use of stannic acid, tannic acid, or orthophosphoric acid. Lakes having great covering power, though the percentage of coloring matter therein is small, can be produced with this aluminum silicate, and have great coloring power'and brilliance.

An example of the manner in which the process can be carried out is as follows. 60 kilograms of crystallized aluminum sulfate dissolved in 1000 kilograms of water are mixed with a 10 per cent. solution of 20 kilograms of calcined soda and 7 5 kilograms of water-glass (40 degrees Baum,). A 10 per cent. solution of .75 kilograms of Glaubersalt is added to this mixture, and then a two per cent. (or weaker) solutionofthe coloring matter, for example 60 kilograms of orange II dissolved in 3000 liters of water;

Specification o1 Iietters Patent. Application filed January 17, 1908. Serial No. 411,321.

rRoeEss or MAKING- LA'KE ooLoRs.

Patented Dec. .1, 1908.

Finally a 10 per cent. solution of approximately 220 kilograms of crystallized arium chlorid is added. The amount of soda retotal alkalinity must be 'suflicient to precipitatethe alumina.

quire'd depends, of course, on the slightly varying alkalinity of the water-glass; the

The process here set forth is by no means identical with the well-known process in which natural aluminum silicate in the form of kaolin or china clay is used. The meth- -ods of using the natural and the artificial silicates are. totally different, by reason of the different physical properties of the compounds. The naturalpwhite silicate," which deteriorates the brillianceand purity of the color, is only used to a very limited extent .for imparting the requisite covering power practically to lakes, and is in this respect equivalent to barium sulfate. rtificially precipitated aluminum silicate does not by any means fulfil the same purpose. It is a transparent, gelatinous substance, resembling more closely the ordinary hydrate of alumina, andmust be used in conjunction with a white substratum adapted to impart ,covering power. I represented 'by the formula 2Al,O,-7SiO is It has been proposed to use, in the manufactu're of lakes, sodium .silicate in. the form of water-glass,

but the water-glass is in that case. to be added at the end of the operation, and only in small quantities, for the purpose of precipitating the coloring matter from the solution on to the aluminum hydrate previously produced in the usual manner.

.What I claim as my Invention and desire States is:--

The method of manufacturing lake colors by precipitating aluminum silicate in the presence of the coloring matter.

' In witness whereof I have signed this asic coloring matter and to secure by Letters. Patent of the United specification in the presence of two witnesses.

I FRIEDRICH MAX WINTER.

Witnesses: I EMIL SCHMIDT,

PAUL 

